Expression of EMT inducers integrin-linked kinase (ILK) and ZEB1 in phyllodes breast tumors is associated with aggressive phenotype

Abstract

Phyllodes tumors (PTs) of the breast constitute an uncommon group of mammary fibroepithelial lesions with ambiguous biologic behavior. Recent evidence suggests that epithelial mesenchymal transition (EMT), a driving force of cancer progression is implicated in PTs pathogenesis. Integrin-linked kinase (ILK), a focal adhesion kinase, has been implicated in cancer and EMT and represents a novel cancer therapeutic target. In this study, we aimed to investigate ILK and EMT markers expression in phyllodes breast tumors in relation to tumor grade. Expression of ILK and EMT markers E-cadherin, β-catenin, Ν-cadherin, vimentin, Snail, ZEB1 and Twist was evaluated by immunohistochemistry in paraffin-embedded tissue sections from 96 human phyllodes breast tumors (48 benign, 27 borderline, 21 malignant). Cytoplasmic and nuclear immunopositivity of ILK were observed in both the epithelial and the stromal component of phyllodes breast tumors and were significantly higher with increasing tumor grade. An EMT-related expression profile consisting of decreased membranous and increased nuclear/cytoplasmic immunoreactivity of Ecadherin and β-catenin and increased expression of Ncadherin, vimentin, Snail, ZEB1 and Twist was observed in tumor epithelial and stromal component and was significantly associated with malignant phyllodes breast tumor histopathology. Interestingly, there was a significant correlation of ILK expression with all of the EMT markers examined. Our results suggest that EMT significantly contributes to phyllodes tumor pathogenesis and originally implicate ILK and ZEB1 in phyllodes tumors malignant phenotype.